When typing in the text input box in an anvil, typing the letter 'N' will move the focus away from the textbox, meaning that you have to click on the textbox again to continue typing.
For example: I want to name an item "Dinnerbone" when N is typed out focus is taken away from the input field and when typing out E the anvil GUI is closed.
This bug only affects Minecraft Windows 10 Edition when using mouse and keyboard.
Reported for test and fix.